Apparatus for the wet concentration of coal by the float and sink process using a heavy separating liquid



-Ma.rch 8, 1938. G. J. DE vooYs 2,110,760

' APPARATUS OF THE WET CONCENTRATION OF COAL. BY THE FLOAT AND SINKPROCESS USING A HEAVY SEPARATING LIQUID Filed March 27, 1936 4Sheets-Sheet 1 L2 WMM Attorneys.

\ nuento'r G. J. DE VOOYS APPARATUS OF THE WET CONCENTRATION OF COAL BYTHE FLOAT AND SINK PROCESS USING A HEAVY SEPARATING LIQUID March 8,.1938.

Filed March 27, 1936 4 Sheets Shee 2 Attorneys.

2,110,760 APPARATUS OF THE WET CONCENTRATION OF COAL BY THE FLOAT March8, 1938. G. J. DE vooYs AND SINK PROCESS USING A HEAVY SEPARATING LIQUID4 Sheets-Sheet 5 Filed March 27, 1936 Fig.7.

lnuenkor 5 PL 7 o W P E.

D e N m a w Z g 1 March 8, 1938. G J, E vo s 2,110,760

APPARATUS OF THE WET CONCENTRATION OF COAL BY THE FLOAT AND SINK PROCESSUSING A HEAVY SEPARATING LIQUID Filed March 27, 1956 4 Sheets-Sheet 4ETSO'TF'O'O I ooooooocuo ooooooooo o ooeooonooooon oog glioooo KInventor EERA/M JZ/v OEVaTJ s Patented Mar. 8,1938

UNITED STATES PATENT, OFFICE LIQUID I 'Gerard Jan devoo'ys, Huckelhoven,near Erkclenz, Germany Application March 2'7, 1936, Serial No. 71,120

, In Germany June '7, 1934 3 Claims.

-5 sion of finely-ground solids in water or other relatively-lightliquid, 'such as described in the United States Patent 2,026,343, andrelates to the regulation and distribution of the "circulation of ltheheavy liquid and to other features which im .10 prove the operation. Theapparatus consists of a concentrating vessel, containing the heavyliquid ii -which the coal is separated into a floating and a sinkingmaterial, and which in its upper part has a device icr drawing oif thefloating materialand in its lower part is in communication with moval ofthe sinking material.

-Theheavy liquid has the same level in this casing as in theconcentrating vessel. On. the

I the casing of a conveyor apparatus vfor the relatter, at-the exitforthe floating material and beneath a grate, is fixed a box into which theheavy liquid drains off from the floating material. Similarly at thehousing of the elevator I mechanism for the sinking material is alsofixed 125 a box into which the heavy liquid, from the sinking. materialdrains. Both these box-like devices are arranged so that the heavyliquid flows out of them over weirs.

The present invention has for its object ,to make 7 it possible, duringworking, to suitably'regulate I under controlled conditions the flow ofthe heavy liquid returning from these outlets into the concentratingvessel, both as regards strength and direction. Furthermore, by means ofthis improved devi there is attained a uniform distribution of Klinecirculating liquid in. the concentrating vesse I N The apparatusaccording to the present invention is characterized by the fact thatheavy liquid 40 flowing put of .the concentrating vessel and/or thecasing containing the elevator mechanism for removing the submergedresidue, is returned to the concentrating vessel by one or more nozzlepipes each of which extends overthe whole width of the said vessel. Thenozzle discharges preferably point in a direction opposite to the inflowof the material to be treated.

' In the concentrating vessel the flow of the liquid is converted orchanged into an upward and/or downward current. These two kinds ofcurrent have for their object to convey, in any desired direction, theparticles of coal which have apparticularly clean coal is desired thesebordering products will be driven into the submerged residue andconsequently the downward current of flow will be increased. If goodgangue is desired, the upward current or flow must be increased. 5

These currents in the co-ncentratingvessel, may be adjusted byregulating the amount of overflow by means of independently adjustableoverflow weirs onsaid vessel and on the elevator mechanism casingcommunicating therewitha Accord-' 10 mg to a further feature of myinvention, the over flow weirs are preferably arranged directly ad'- Ijacent to each other, so that a single, glance sufflces to determine theratio of the overflow. As only the ratio of the-overflows to each otherhas l5 any influence on the obtaining of a good separation in theconcentrating vessel, the absolute overflow quantities are of noimportance.

By means of one or more'nozzle pipes, the heavy liquid coming from theoverflow weirs is car- 20 ried uniformly over the whole width of the comI centrating vessel and/or preferably in a direction opposite to that ofthe inflow of the coal. With this arrangement the material undertreatment is spread out or loosened by the'opposing slight up- 25 wardcurrent, so that the treatment can act on said material moreeffectively. This weak upward current is then gradually changed to ahorizontal concentrating vessel. Since particles of the treated materialremain is suspension in the circulating 35 heavy liquid, there is thedanger of the slots of the nozzle pipes becoming clogged. In order toobviate this defect, mechanical or hand-operated cleaning devices arearranged inside the pipes,

.which devices constantly keep clear the nozzle 40 suitable manner onthe material delivered for concentration, the nozzle pipes areadjustable in b the horizontal direction. The nozzle pipes may becarried in stuffing boxes, which in turn may be carried by cover plates,which fit closely round the stufling boxes 'andto the sides oftheconcentrating vessel and whicl'iare large enough to cover the slotopenings and adapted to be bolted to the side casing oi! theconcentrating vessel, so that, when adjusted in position no leakage canoccur. The nozzle pipes can be moved in the slots in a horizontaldirection by suitably positioning the cover plates. It' is thus possibleto bring. the nozzle pipes .nearer to the material delivered and thecurrents can be caused to act upon the particles at a point nearer orfarther from the feed, as may be desired. Also, the nozzle pipes areadjustably rotatable in the stufllng boxes, so that the incoming liquidcan be caused to enter at any desired angle. The eifects of theseadjustments of the nozzle pipes are local and result in beneficialefiects in the treatment, according to particular requirements. Theyare, however, independent of the main control of the strength of theupward and downward currents which is determined, as previouslyexplained, by the quantities overflowing at the weirs.

The method of operation of the current is improved if the material to betreatedis well wetted with the heavy liquid. A' badly wetted materialtends to agglomerate, so that the separation of the sinking and thefloating substances is prevented. A good wetting of the niaterial to betreated can for example be effected by thoroughly stirring the materialin the heavy liquid. For'this purpose, there are fitted on the inletside of the concentrating vessel, over the whole width of the wall,pipes through which compressed air or the like is blown or brought intothe liquid. The latter thereby. bubbles up and the material to betreatedlis stirred up therein. As only a wetting of the "surface of theindividual grainsis important, a' narrow eddying zone at the inlet sideof the concentrating vessel is sufficient.

The separation of the material under treatment takes place over theentire length of the vessel. It is, important to provide means whichwill insure the carrying out of this separation without the formation ofharmful or disturbing eddies and under avoidance of too strong currents.

A constructional example of the improved apparatus is shown in' theannexed drawings, in,

which Fig. 1 is a sectional elevation/i of the whole device.

Fig. 2 is a sectional elevation along the line 2--2 of Fig. 1, showingthe overflow weirs on'the concentrating vessel and on the casingof theelevator mechanism for the discharge of the sinking material.

Figs. 3 and 4 illustrate a nozzle pipe with a cleaning device adaptedfor rotation.

Fig. 5 shows a nozzle pipe adapted for displacement in the vessel wall.

Fig. 6 is a section on the line 6-6 of Fig. 5.

Fig. 7 is a diagrammatic illustration of the supply of heavy liquid.

Fig. 8 is a section through the discharge bucket on the line 88 of Fig.9.

Fig. 9 is a plan of the concentrating vessel showing the dischargebucket and the endless rake conveyor.

l indicates the concentrating vessel which in the example shown is ofrectangular cross-section and tapers conically towards the bottom. On tothis lower part is connected a casing 5 which communicates with the saidvessel. .The

, casing contains conveyor means fpn carrying I away the sinkingmaterial, for example, a bucket conveyor or elevator mechanism. Thewhole is mounted in 'a suitable frame 2|. The-material to be separated,such as coal is introduced in the direction ofthe arrow through a feedtrough 2 or thedike. The floating coal is removed by a rake conveyor 3over the-discharge slope 4 having the same width as the concentratingvessel. The submerged particles are removed by the elevator mechanismfrom the lower conical part of the concentrating vessel. The overflowingheavy liquid. passes partly at the outlet end of the concentratingvessel into a box-like container l6 over a weir with an adjustable slide-or gate 25 and/or partly at the casing of the sinking materialelevator, through a box-like discharge I! over, a. weir with anadjustable slide or gate 26 level of the liquid and thereby also aregulation of the currents 8 and 9 in the concentrating vessel ispossible. The-weirs, for purposes of, better estimating the flow of theheavy liquid can be arranged adjacent to eachother on the concentratingvessel and on the elevator mechanism casing (Fig. 2).

It will thus be seen that the strengths of the upward and the downwardcurrents in the concentrating vessel l are in direct proportion to therelative quantities overflowing from the weirs at the outlets of theconcentrating vessel, and that of the sinking material elevatormechanism 5.

The nozzles pipes 6 are fitted in the slots l0 made in the containerwall and are movable in a horizontal direction; the slots 1 may bedirected towards the inlet. The closure or seal towards the outside ofthe container is effected for example by a special stuffing box l3 (Fig.4).

In Figs. 5 and 6 I have shown, by waypf example, an embodiment of anozzle pipe adjustable. in a horizontal direction The nozzle pipe 6'extends through the slot Ill of the vessel wall and has a plate 3|covering this slot and which the plate 3| are carried slidably in thecover .plate 32.

In Figs. 3 and 4 I have shown an embodiment of a rotatable nozzle pipe'6. The arrangement of the nozzle pipe in or on the concentrating vesselis shown by way of example in Figs. '7 and 9. It will be understood thatthe nozzle pipes can be of any desired cross-section, for example,circular or rectangular. The slots 1 of the nozzle pipes (Figs. 3 and 4)are safeguarded against clogging by a special cleaning device. Thisconsists of a rod II which carries lugs or pins l2. The rod H can bereciprocated backwards and forward in the longitudinal direction of thenozzle pipe.

In order to improve the working ofthe currents, it is important that thematerial to be treated should be well wetted by the heavy liquid. Forthis purpose there are fitted'at the inlet of theconcentrating vessel,tubes'lil provided with holes 20 through. which compressed air or thelike is brought into the heavy liquid.

The separation takes place following on the wetting zone over the wholelength of the concentrating vessel. For this purpose, the rake conveyor3 is arranged to slide so closely against the walls of the concentratingvessel (Fig. 8) that a box-like space is formed between each twoadjacent carriers in which the clean coal is brought to the dischargewithout harmful eddyings (Fig. 1). r

In order to prevent sinking material which may be retained between theclean coal, from being discharged with this, an arrangement has beenmade which permits a careful loosening'of the clean coal. .For thispurpose the b0x'22 into which the liquid drains from the clean coal isconnected, at its lower part, by a box or tubular system with theconcentrating vessel I. There is arranged in the latter, behind theinlet openings, an upwardly inclinedpartition 34 whichdefleets thecurrent upwards. To prevent clogging of the tubes 30, there is provideda sieve 33. By this improved construction a very slow. current produced,loosening by its upward motion,

the clean coal to such an extent that any confined sinking productparticles can drop out. The sticking of pieces of coal between the rake.con-

veyor and the vessel wall is also prevented by this current. i

As I have stated above, the discharge slope 4 has the same width as theconcentrating vessel I, and the rake conveyor 3 is arranged to slide inclose contact with the walls of said vessel and therefore also with thewalls of the discharge slope 4, see Fig. 8. The box-like spaces orcompartments formed between adjacent bars or carriers of the conveyor 3while such bars travel in contact with the said walls will thus beclosed and separated or sealed from each other. material in saidcompartments will therefore be carried along in a relatively quiescentcondl-' tion, without any agitation or eddying. This is an importantfeature in assuring an eflicient separation of the constituents, sincethe material under treatment should be as undisturbed as possible duringthe separating operation.

. Another advantage of my invention resides in the fact that theconveyor 3 maybe operated at relatively high speed, thus increasing theoutput of the separator per unit of time. This result is due partly tothe close fit of theconveyor members against the walls of the recep-The.

is discharged into the receptacle l at the upwardly inclined or curvedpartition 34, thereby producing a slight upward current at the upperportion of the receptacle, which current lifts the floating coal overthe discharge edge of the receptacle so that such coal maynot get caughtor jammed between said edge andthose of the traveling conveyor members.The upward current of liquid issuing from the conduit 30 (through thescreen 33) also contributes to separate or drive apart the floating coalbodies, so that small particles contained between them may drop downbefore reaching the discharge edge of thereceptacie.

' I claim:-

. 1. An apparatus for the separation of substances of difierent specificgravities by the float and sink process using a heavy separating liquid,comprising a concentrating vessel provided at its upper portion with aninlet for the material to be treated and with an outlet for the liquidand the floating products, a conveyor movable in said outlet to carryaway the floating products, a container communicating with said outletto receive liquid therefrom and provided with an overflow, a pump havingits intake connected with the overflow side of said container and itsdelivery connected with said vessel, and a connection by-passing saidpump for carrying liq- .uids from said container directly to saidvessel,

and means for removing the sinking product from the lower portion ofsaid vessel.

2. An apparatus for the separation of substances of difierent specificgravities by the float and sink process usinga heavy separating liquid,comprising a concentrating vessel provided at its upper portion with aninlet for the material 'to be treated and with an outlet for liquid, and'means for returning to the concentraing vessel the liquid flowing. outat the upper portion thereof, said means including one or more dischargepipes extending in said vessel and movable therein bodily toward andfrom said inlet, said pipes passing through the walls of the vessels,and covers slidable in unison with said pipes and preserving tightjoints at the points where such pipes pass through the walls of thevessel.

-3. An apparatus for the separation of substances of different specificgravities by the float and sink process using a heavy separating liquid,comprising a concentrating vessel provided at its upper portion with aninlet'for the material to be treated and with an outlet for liquid, andmeans for returning to the concentrating vessel the liquid flowing outat the upper portion thereof, said means including one or more dischargepipes extending in said vessel and provided with outlet openings, saidpipes being journaled to turn about their longitudinal axes so as tochange the direction in which their outlet openings point.

GERARD JAN n: VOOYS.

